At least one person was killed and a number of others wounded Tuesday when up to four grenades exploded outside the main courthouse in the eastern Belgian city of Liege, media and witnesses reported.

RTL-TVI said the incident began when a man threw a grenade into the courthouse, with the Belgian press saying a further device was thrown and detonated, with gunfire being heard and police seen pursuing attackers. Police were not immediately contactable to confirm the toll or events.